1. Field of the Invention:
This invention relates to a recording or reproducing apparatus and more particularly to a recording or reproducing apparatus capable of recording or reproducing audio signals.
2. Description of the Related Art:
Generally, audio signals can be recorded, along with video signals, on a recording medium such as a magnetic sheet for use in, e.g., still video systems.
The invention will be described below by way of an example of the format of a still video camera.
Fifty concentric tracks are formed on a magnetic sheet used in the still video camera exemplified, and this magnetic sheet is rotated about a rotational shaft at a speed of 60 cycles per second.
To effect audio signal recording in these tracks, an audio signal is compressed on the time base to be increased in the frequency and is thereafter frequency-modulated and recorded. An audio signal for a length of time of, for example, 10 to 20 seconds can be recorded in one track. The length thereof depends on the ratio of the compression on the time base.
However, it has only been possible to record or reproduce a monophonic sound by employing this recording or reproducing apparatus. It has not been possible to effect a recording and reproducing process with respect to an audio signal with, e.g., stereo signals which require two channels when recorded or reproduced.
Two tracks may be formed, one for an L+R signal and the other for an L-R signal (an R signal is an audio signal in a right channel, and an L signal is an audio signal in a left channel), to record stereo signals. When these signals are reproduced, the signals picked up from these tracks undergo addition and subtraction processes, thereby obtaining the R and L signals. However, this method entails a problem in that sometimes the signal from the track in which the L-R signal is recorded is the only one reproduced, instead of both of the signals recorded in the tracks in this manner being produced simultaneously.